Parallel lines have heretofore been made in a variety of techniques, all of which are time-consuming. A calculation is first made of the spacing necessary to depict rows of bricks, for example, and a ruler is next disposed vertically of the paper or other material on which the drawing is made. The dimension is then measured off line-by-line with a sharp pencil. A horizontal straight edge is then lined up successively with the pencil marks and the parallel lines are then drawn. Also a wheel with a spiral arrangment of holes is slid along a straight edge and a pencil point is placed in successive holes to draw a group of parallel lines.
Another technique is to set dividers at the calculated dimension and walk them vertically across the paper. The dividers leave pin pricks in the paper which the draftsman later locates and uses these for the reference points in drawing horizontal parallel lines.
Other techniques employ proportional scalers, especially where no ruler or scale is available for the particular spacing calculated for the spacing between parallel lines.